The invention relates in general to vehicle wheels and in particular to a method for fabricating a bimetal vehicle wheel.
Vehicle wheels include an annular wheel rim which is adapted to carry a pneumatic tire. A circular wheel disc is typically formed across an end of the wheel rim. Alternatively, the wheel disc can be recessed within the wheel rim. The wheel disc includes a wheel hub having a central pilot hole and a plurally of wheel stud holes formed therethrough for mounting the wheel upon a vehicle. Typically, the wheel disc also includes a plurality of wheel spokes connecting the wheel hub to the wheel rim.
In the past, vehicle wheels have been fabricated by attaching a stamped steel wheel disc to a rolled steel wheel rim. Also in the past, vehicle wheels have been cast from molten steel alloys or forged from steel alloy billets. Increasingly, vehicle wheels are being formed from light weight metals, such as aluminum, magnesium, titanium, or alloys thereof. Such light weight wheels can be formed with the wheel disc having a pleasing aesthetic shape. The wheel disc outer surface is typically machined to form a smooth surface which can be subsequently finished with a decorative high luster. It is known to form light weight wheels from a one-piece casting or forging. Alternately, light weight wheels can be assembled by attaching a wheel disc to a wheel rim or a full faced wheel disk to a partial wheel rim.
An assembled light weight wheel having a wheel disc and rim formed from dissimilar metals is known as a bimetal wheel. For example, a full faced wheel disc cast or forged from an aluminum alloy and having a specific shape can be welded to a partial wheel rim rolled from a steel alloy. In this example, the use of the aluminum alloy wheel disc allows styling of the visible portion of the assembled wheel while the use of the steel alloy wheel rim reduces the cost of the wheel. To facilitate welding the steel alloy wheel rim to the aluminum alloy wheel disc, it is known to cast a steel alloy weld anchor into the wheel disc. A portion of the weld anchor remains exposed and forms at least a portion of the surface of the wheel disc which contacts the wheel rim. The wheel rim is welded to the weld anchor with the weld anchor providing a compatible material for forming a weld with the steel wheel rim.